Sodium is not explosive in its elemental form. However, it is highly reactive with water, producing hydrogen gas which is flammable and can ignite upon contact with the sodium.

Here's a breakdown:

* Explosive: Sodium itself doesn't explode. However, the reaction with water can create a violent explosion due to the rapid production of flammable hydrogen gas.

* Radioactive: Sodium is not radioactive.

* Noxious: Sodium is noxious in the sense that it can cause severe chemical burns upon contact with skin or eyes.

It's important to handle sodium with extreme caution due to its reactivity with water and the potential for burns.